Reference Angle Section Question

Trigonometric ratios and functions, the unit circle, inverse trig functions, identities, trig graphs, etc.
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Reference Angle Section Question

Postby hiroze » Sat Apr 17, 2010 11:50 pm

This question is in the exercises associated with reference angles. I understand the reference angle part, but there is a question, which I don't know how to work with or without a calculator.

Approximate to three decimal places:
a) sin 73deg 20'
b) cos 0.68

The answers are a) .958 and b) .778 though I don't know where to start. I don't know what the 20' means either.

I looked through the web for some info and the purplemath sections, but I can't get it to work out :confused:

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Postby stapel_eliz » Sun Apr 18, 2010 11:32 am

I don't see any way to use reference angles for these...? :confused:

To learn about the "degrees, minutes, seconds" notation, try here. Your calculator should be able to handle this notation; check the manual for how to enter the information.

To find these sine and cosine values, you'll either need to use a calculator and round, or else work from trig tables in your book. Look in your text to see how it did similar exercises, and follow that lead. :wink:

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